In November 2015, when gunmen attacked Paris, France declared war on the Islamic State. But that war - and France's 'year of terror' - began a year ago with the attack on satirical magazine Charlie Hebdo. With unprecedented access to the French authorities and previously unseen footage, five-time Bafta-winning director Dan Reed reveals the untold story of the massacre and of the first Islamic State strike in Paris at a kosher grocery store. Key witnesses, police officers and survivors - many speaking for the first time - piece together the dramatic attacks and the unprecedented manhunt that gripped the world for three extraordinary and terrifying days.

This is the definitive story of the Charlie Hebdo massacre in January 2015, and of the three days of horror that followed, leaving twenty dead and a nation traumatised. A true ticking-clock film, the documentary will be structured tightly around the three days of terror. The keyword is immediacy, so that we feel like we’re watching a drama, but where real lives are at stake, and every word is true. The film will unfold in the present tense, using UGC and police footage to take us into the heart of the action and, providing the emotional heartbeat of the film, powerful interviews with those who were there.